Attempt to optimize sandstorm build

Reduce build time

.travis.yml

@@ -60,7 +60,8 @@ script:
 - cd /home/vagrant/bundle/programs/server && "$METEOR_DEV_BUNDLE/bin/npm" install
 - cd $TRAVIS_BUILD_DIR/.sandstorm
 - sed -i "s/\sid = .*/$SANDSTORM_ID/" sandstorm-pkgdef.capnp
-- ./build.sh
+- mkdir -p /home/vagrant/bundle/opt/app/.sandstorm/
+- cp /opt/app/.sandstorm/launcher.sh /home/vagrant/bundle/opt/app/.sandstorm/
 - sed -i "s/\spgp/#pgp/g" sandstorm-pkgdef.capnp
 - spk pack $TRAVIS_BUILD_DIR/rocket.chat.latest.spk
 - cd $TRAVIS_BUILD_DIR